Dramatic results from experimental prostate cancer treatment

2 July 2009
Dramatic results from experimental prostate cancer treatment
by George Atkinson

An experimental drug therapy used in combination with standardized hormone treatment and radiation therapy has completely eradicated what were considered to be inoperable prostate cancers in two patients. The men were participating in a Mayo Clinic clinical trial of an immunotherapeutic agent called MDX-010, or ipilimumab.

"The goal of the study was to see if we could modestly improve upon current treatments for advanced prostate cancer," said Mayo's Eugene Kwon, the leader of the trial. "The candidates for this study were people who didn't have a lot of other options. However, we were startled to see responses that far exceeded any of our expectations."

The patients first received a type of hormone therapy called androgen ablation, which removes testosterone. The researchers then introduced a single dose of ipilimumab, an antibody, which kills massive numbers of tumor cells. Both men experienced consistent drops in their prostate specific antigen (PSA) counts over the following weeks until both were deemed eligible for surgery. Then, during surgery, came a greater surprise.

"The tumors had shrunk dramatically," says Mayo co-researcher Michael Blute, who operated on both men. "I had never seen anything like this before. I had a hard time finding the cancer. At one point the pathologist [who was working during surgery] asked if we were sending him samples from the same patient."

Both patients have now resumed their regular lives. Further research is being planned to understand more about the mechanisms of the antibody and how best to use the approach in practice. The researchers, however, note the significance of their findings. "This is one of the holy grails of prostate cancer research," says Kwon. "We've been looking for this for years."

Related:
Statins investigated as prostate cancer treatment
Prostate Cancer Drugs Found To Addle The Brain
Radiation Therapy Scaring Off Prostate Cancer Patients

Source: Mayo Clinic